A major electricity infrastructure project is set to boost energy security, enable decarbonisation, and support future growth across eastern Southland with The Power Company Limited (TPCL) announcing plans for a new 110kV overhead line known as the Hokonui Line.

The project is a partnership between TPCL, Transpower and Fonterra, and will see a 12.5km PowerNet line constructed between a new Transpower substation on Cuttance Road and a new Fonterra substation at Fonterra’s Edendale site.

TPCL Group Chair Peter Moynihan said the Hokonui Line was a critical investment in Southland’s future.
“This project ensures our network has the strength and resilience needed to meet increasing demand, support industry, and enable the transition to a low-emissions economy. It’s also a great example of what can be achieved when infrastructure partners work together toward a common goal – and we’re proud that PowerNet, as part of the TPCL group, will be delivering the build”

The new line will deliver the increased capacity needed to support industrial growth in the region. It will help power Fonterra’s new UHT plant, which is currently under construction, along with key site upgrades such as two new electrode boilers. The line also plays an important role in supporting Fonterra’s transition away from coal.

Construction of the project will begin in November 2025, with the line build scheduled to commence in September 2026. The full project is expected to be completed by August 2027.

Transpower Acting Executive General Manager External Affairs Diana Price said investment in electricity infrastructure today will ensure the power system is serving New Zealanders now and into the future.

“This project will increase electricity capacity in Southland for Fonterra and bring wider power security benefits for the region. We’re pleased to be working alongside PowerNet, and this investment shows our shared commitment to supporting local people and businesses to thrive by enabling a lower-emission future.”

Fonterra General Manager Energy and Climate, Linda Mulvihill highlighted the importance of infrastructure investments like the Hokonui Line in enabling industrial decarbonisation and supporting long-term sustainability goals for both the Co-operative and the country.

“At Fonterra, we are committed to transitioning to more sustainable energy sources. When evaluating the best energy options for our decarbonisation projects, we consider a range of factors, including security of supply, cost, and overall sustainability outcomes.

“The Hokonui Line is an important step in enabling the Edendale site’s transition, providing the reliability and electrical capacity needed to support site upgrades like our new electrode boilers and UHT plant.”

Designed to minimise disruption, the project team is engaging early with stakeholders and landowners to ensure clear and consistent communication throughout the build.

This investment will help decarbonise one of New Zealand’s major industrial sites while supporting growth in one of eastern Southland’s and New Zealand’s, major primary industries. It will also bring wider regional benefits through job creation and improved network performance.